Influence of pitanga (Eugenia uniflora L.) leaf extract and/or natamycin on properties of cassava starch/chitosan active films

Active edible coatings and films produced by addition of plant extracts and antimicrobial compounds are of interest for food packaging. The aim of this work was to develop and characterize film-forming solution and film based on blends of cassava starch/chitosan (CS/CH) incorporated with pitanga (Eugenia uniflora L.) leaf extract (PE) and/or natamycin (NA), produced by casting, and studying their effect on selected physical properties, and antioxidant and anti-fungal activities of films. The addition of PE did not affect the film mechanical properties, whereas NA significantly decreased the flexibility of films due to changes in biopolymer behavior from ductile to brittle. Structural analyses by FTIR and XRD indicated interaction among the components particularly with presence of new C=O vibration peaks and shift in the characteristic CS/CH blend wave numbers. The antioxidant activity of films increased significantly with PE although the combination of additives resulted in activity reduction. Positive anti-fungal effect of NA containing films was observed against Aspergillus flavus and Aspergillus parasiticus, indicating potential for active food packaging applications.